Plant Ecology of the Sonoran Desert Region - Design with the Desert: Conservation and Sustainable Development - page 149

8
Plant Ecol ogy of the Sonoran Desert Region*
Mark A. Dimmitt
CONTENTS
8.1 Introduction ........................................................................................................................ 151
8.2 Basic Plant Anatomy and Classification ......................................................................... 152
8.2.1 Classification and Plant Identification ................................................................ 152
8.3 Photosynthesis ................................................................................................................... 154
8.4 Coping with Desert Climate ............................................................................................ 155
8.4.1 Succulence ............................................................................................................... 155
8.4.2 Getting Water ......................................................................................................... 156
8.4.3 Conserving Water .................................................................................................. 157
8.4.4 Protection ................................................................................................................ 158
8.4.5 Drought Tolerance ................................................................................................. 158
8.4.6 Drought Evasion .................................................................................................... 160
8.4.7 Combined Drought Adaptations ......................................................................... 164
8.5 Adaptations to Other Desert Conditions ....................................................................... 164
8.6 Pollination Ecology and Seed Dispersal of Desert Plants ........................................... 165
8.6.1 Seed Dispersal ........................................................................................................ 167
8.7 Invisible Larder .................................................................................................................. 168
Further Readings ......................................................................................................................... 168
8.1 Introduction
You could easily recognize a desert even if you were blindfolded. You would discover that
you can walk fairly long distances without bumping into plants, and when you do the
encounter is likely to be painful. Even standing still there are unmistakable clues about
your location. You can feel the arid atmosphere pulling moisture out of your body. The
intense sunlight actually creates a sensation of pressure on your skin. On really hot, dry
days you can smell the parched vegetation that is literally toasting and filling the air with
pungent terpenes and aromatic oils.
Most desert plants also look different from those in other habitats; they are often spiny,
almost always tiny-leafed, and rarely “leaf green.” Many have bold, sculptural growth
forms characterized by swollen stems or starkly exposed stems unconcealed by foli-
age. At the other extreme is a unique desert growth form that landscape architect Iain
* Adapted with permission from Plant ecology of the Sonoran Desert Region, in Phillips, S.J. and Comus, P.W.
eds., A Natural History of the Sonoran Desert , Arizona-Sonora Desert Museum Press/University of California
Press, pp. 128-151, 2001.
151